Let's make a short list of pros and cons of downstate in WvW. I'll start with mine, but feel encouraged to add you own points (as long as you give constructive reasoning for them - "We also had downstate" is not constructive, not is "Downstate sucks" or "Everything would be better without downstate"):
- Downstate adds the ability to rally (avoiding being defeated) if you or you allies can defeat another enemy swift enough, adding another layer of complexity/strategy to the battle.
- Downstate is used in PvE & PvP, so removing it might confuse newer WvW players that come freshly from PvE & PvP.
- Downstate reduces the amount of downtime (no pun intended) as downed players can still use skills or rally, quickly returning to the fight, while defeated players need to use the nearest WP and run back (unless resurrected)
- Downstate turns large-scale battles into "winner takes all" as downed players of the winning side will rally when the losing side is defeated. This prevents a stronger side from suffering attrition (i.e. losing parts of its members), thus encouraging blobbing (as even a narrow defeat to another group will have next no impact on that group, as most of their downed players will rally)
- Downstate affects small-scale combats negatively; in e.g. a 2 vs 2 situation with one downed player on each side, the first side that manages to defeat their downed opponent gains significant advantage, as their down player rallies, turning the fight into 2 vs 1.
- Downstate turns NPC allies into a liability, as enemy downed players can rally upon a NPC ally's death (be it caused by conditions or downed-skills on the player). You having allies should not be an advantage to your opponent.